1. Field of the Invention
The present invention relates to a testing apparatus. More particularly, the present invention relates to a testing apparatus performing a test by supplying a current to a device under test.
2. Description of the Related Art
Recently, as highly integrated and high speed semiconductor devices have been realized, low voltage and high current devices are rapidly being developed. Accordingly, also in a testing apparatus for performing a test on a semiconductor device, it is required to operate with high performance, high speed load response, and high efficiency and to respond to low voltage and high current.
FIG. 1 shows an equivalent circuit of a testing apparatus 100 according to the prior art. And, FIG. 2 shows the frequency response characteristics of a voltage V0 applied to a device under test 104 by the testing apparatus 100 shown in FIG. 1. The testing apparatus 100 adopts a voltage output amplifier 102, and performs a test of the device under test 104 by applying the voltage V0 to the device under test 104. Here, since the gain bandwidth (GBW) product of the voltage output amplifier 102 is calculated by 1/(2πRC) [Hz], it is considered that the resistance R should be small for realizing a high speed test. However, it is difficult to lower the resistance R sufficiently in the testing apparatus 100 adopting the voltage output amplifier 102, and thus the high speed test is restricted and the high speed load response cannot be realized sufficiently.